Income Taxes - Future Commitments of the Low Income Housing Investments (Details) - Low income housing investments - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Future Commitments
Future commitments	$ 845	$ 1,271
2016	123
2017	14
2018 through 2023	$ 708

Minimum amount of other commitment maturing in the next fiscal year following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitmentDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant